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Advanced Micro Devices, the second largest x86-64 chip designer, is between a rock and a hard place. Although it recently went “fabless” by giving up its ownership stake in GlobalFoundries to shed some debt, the x86 underdog is surrounded by the booming (primarily ARM-based) mobile market on one side, and chip juggernaut Intel — which has vastly more resources to devote to pursuing new (smaller) process nodes, and CPU technology — on the other. Further, both ARM and Intel are moving towards a point of convergence as Intel’s x86-based CPUs get smaller and more efficient, and ARM’s SoC (system-on-a-chip) processors continue to get faster and add functionality. This raises the question of where exactly that leaves AMD.

At the Hot Chips conference today, AMD CTO Mark Papermaster provided an answer as he spoke about the future and continued relevance of AMD. In many respects, the keynote reiterated the company’s intention to bet its future on (the success of) APUs — an idea first revealed at the AMD Fusion Developer Summit (AFDS) earlier this year. The overarching theme at AFDS was that AMD was adapting to the current state of affairs, and would be — to a certain extent — conceding the high-end desktop market to Intel. Rather than compete directly against Intel for the absolute fastest performing chip crown, AMD has decided to focus on the areas where it has the biggest advantage over the competition. Primarily, the company’s fortés include graphics processing and heterogeneous computing architectures.

AMD talked heavily of the graphics processing portion and unified address space in its next generation Kaveri APU at AFDS. However, in today’s keynote, the chip designer focused on the CPU side of things by talking about the Steamroller x86-64 CPU architecture. Steamroller is the successor to Piledriver, and Piledriver is the name of the x86-64 CPU architecture used in the (upcoming) Vishera desktop processors and Trinity APUs. Steamroller will further improve upon Piledriver’s refinements to the original Bulldozer architecture, making it a much more efficient overall design.

AMD has done away with hand-drawn processor schematics (which define how all the internals are laid out and interconnected) in favor of using a computer-assembled design (a more automated design approach). Using a high density library, the company was able to achieve a claimed 30% reduction in power draw and die area in the final chip without reducing the number of logic blocks. The Steamroller cores further boast reduced latency, increased bandwidth, instruction fetching and pipeline optimizations, inter-process communication tweaks, power efficiency improvements, and a dynamically-sized (shared) L2 cache. In simple terms, Steamroller is Piledriver 2.0 — a slightly tweaked Piledriver architecture with processing and power efficiency in mind.

On the instruction-fetching front Steamroller has been heavily refined, and should reap some decent performance gains due to its ability to keep the CPU cores (modules) fed with data. It features a 20% reduction to branch prediction errors, and 30% fewer cache misses, for example. Further, the floating point (FP) scheduler in Steamroller continues to be shared between two CPU modules (cores). It features two 128-bit FMAC (fuse-multiply-add capability) units, but it has only one MMX unit — versus Piledriver’s two MMX units. AMD has stated that this change is in response to changing computing situations, and by removing the MMX units they can reclaim die space without too large of a performance hit.

When Steamroller CPU cores are used in an AMD APU specifically, they are able to realize further power-saving features. Namely, the chip is able to dynamically adjust clockspeeds (and as a result power usage) depending on the current workload. If the CPU is sitting mostly idle and only the GPU is under load (watching a hardware-accelerated H.264 encoded movie for example), the majority of available power can be allocated to the GPU along with increasing the clockspeed (if necessary) up to the rated TDP thanks to AMD’s Turbo Core technology (no word yet on default or boost clockspeeds).

AMD has recognized the importance of, and need for, power efficient processors as millions of mobile devices are sold each year and people are increasingly turning to the internet to store and process their data — where servers eating up electricity and requiring extensive cooling can be major operating expenses. It remains to be seen whether or not AMD made the smart bet in basing the company’s future on APU technology, but the Steamroller cores bring some promising improvements to the table that may just help the company realize its goal of bringing HSA to the here-and-now (and keeping the company competitive as a result).

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I’m not sure, I haven’t followed the PS4 that closely, it’s still a ways off from what I understand (both Sony and MS are milking the current platforms for everything they can :). It may well change, but an APU-powered console would be neat!

It’s not clear if it will be Trinity or Kaveri though… Kaveri would be really cool because then you have the shared GPU+CPU memory area and the consoles should see a decent performance boost there :D

jalebi Singh

it is custom. it is 2x a4 temash chips but the gpu is about the performance of a 7850 non ghz edtion. the cpu is weak but games dont use cpu much so sony was being wise and got a better gpu with the spare cash, so it’s kaveri mixed with features of temash (tablet cpu)

BigOkieTechie

Phenom II was such a promising chip. If AMD would just have driven it core-wise toward Opteron’s direction (go x8 and x12) and use a lower vCore and what not to manager temps, I think they would have done well. Whoever drove the “module” concept at AMD should be shot, IMHO.

timverry

hehe, yeah I’m not sure why they did that. It was a bit too forward looking and AMD was not able to hit the clockspeed, temps, and instructions per clock that they wanted to hit with Bulldozer so it was never at good as it was suppose to be. Here’s hoping Piledriver cores can turn that around and give us the chip that Bulldozer was supposed to be :). Personally, I’m excited for Kaveri but I guess we’ll see :)

BigOkieTechie

I’m just watching. I got a FX-8120 and it (CPU + mobo + SSD) is developing lag issues…so, I gotta figure out what the issue is there. I’m tempted just to go to gaming on my 1090T or 960T that’s unlocked and stable on 6 cores.

Madeline Hoover

available power can be allocated
to the GPU along with increasing the clockspeed (if necessary) up to
the rated TDP thanks to AMD’s Turbo Core technology (no word yet on
default or boost clockspeeds).